This goes in the file includes/classes.php as you can see in the diff.
I’m starting to think the lines I added should actually be placed before the CF7 shortcodes are evaluate though, because then a user might have shortcode in their input which would get evaluated. This probably wouldn’t be a security concern, but might cause some unexpected results. Just add the lines a little earlier, but I don’t remember how much and don’t have the files on this computer to check.